Telephone transmitter.



F. G. WARRELL.

TELEPHONIG TRANSMITTER. APPLICATION rum) 0013, 1907.

901,570. Patented 0015.20, 1908.

\ UNITED STATES PATENT OFFICE FREDERICK G; WARRELL, OFLANSDOWNE'PEIINSYLVANIA, ASSIGNOR TO THE EUELEOTRIG 00., A CORPORATIONOF NEW JERSEY.

'mmarnomc TRANSMITTER.

Specification of Letters Patent.-

Patented Oct. 20, 1908.

Application filed October 8, 1907. Serial No. 895,748.

To 'all whom 'it may concern: Be it known that I, FREDERICK G. WAR-RELL, a citizen of the United States, residing mitter to be made ofsmall dimension and dispense with an induction coil for batterypurposes, and adapting it to be used for long or short distances withequally good results.

Figure 1 represents a side elevation of a telephonic transmitterembodying my invention. Fig. 2 represents a longitudinal sectionthereof. Fi s3 and 4 represent perspective views 0 detached parts. Fig.5 represents a side elevation of a modification of a member of thedevice. Fig. 6 represents a section thereof on line xa:.

Similar letters of reference. indicate corresponding parts. in thefigures.

Referring to the drawings designates a shell or casing, on the interiorof which is the insulatin material 'B, which extends as a lining arounthe same, said casing constituting one pole of the transmitter.

O esignates an annulus or ring of insulating material, which is locatedWithin the shell A and rested againstthe shoulder Don the said wall ofthe casing. Connected centrally with said ring is the carbon E, to whichis attached the wire or conductor F, which. extends therefrom through anopening in the casing A, said carbon constituting the other pole of thetransmitter.

The end of the casing opposite to the ring 0 is rimarily open to permitaccess to the interior thereof, the same bein closed by the diaphragm G,which is retains in position by the cap H, the latter being attached tothe shell A in any suitable manner. .On the back or inner face of saiddiaphragm G is the carbon J, which is secured thereto in any suitablemanner. On the inner face of said diaphragm G is a coating or lining Kof insulating material, the same also surrounding the periphery of thecarbon J. y

Within the chamber formed the casing A and interposed between the ringC, carbon E, lining K of the diaphragm G and carbon J is a filling L ofcarbon in granular or pow- .said diaphragm and t dered condition,whereby the electric current is carried from the carbons or poles E, Jthrou h said filling L. It will now be seen that tie poles E, J areseparated for a con siderable distance, but owing to the filling L, withwhich they are in contact, the current is carried from pole to polethrough the filling, and thus there is a high internal resistance, whichallows the transmitter to be made of a small size, while at the sametime an-induction coil is dispensed with, and the transmitter may beused for long as well as short distances.

While I have described the members E, J as carbons, and the filling L asof carbon, it

is evident that the same may be formed of other conducting material.

While I have specified. certain means for carrying out my improvements,I do not wish to be limited exactly to the same, but desire to make suchchanges asmay come within the scope of the novelty involved, as forinstance, in Figs. 5 and 6, the ring or annulus C shown at G in theother figures is provided with a plurality of carbons E, the result ineither case being the same. 7

Having thus described my invention, what Iclaim as new and desire tosecure by Letters Patent, is

1. In a telephone transmitter, a diaphragm, a casing, oppositelydisposed poles,

therein, a filling of loose material in the said casing, means forinsulating one of said poles and said loose material from said casing,said other pole being secured to said diaphragm, and insulation coverinthe rear surface of he periphery of said latter p0 e.

2. In a telephone transmitter, a' diaphra m, a casing, said diaphragmbeing secure at its periphery to said casin oppositely disposed poles insaid casing, a lingof loose material in said casin means for insulatinone of said poles andhaid loose material rom said casing, said otherpole bein secured to the center of said dlaphragm, an lnsulationcoverlng the rear surface of said diaphragm and periphery of said latterpole.

3. In a telephone transmitter, a diaphragni, a casing, oppositelydisposed poles therein, loose materia in said casing forming a completeconductor from pole to pole,

means for insulating one of said poles. and

said loose material from saidv casin the other pole being non-insulatedfrom sald-casing and secured to the center of said diatherein, loosematerialinsaid-casing forming hragm and insulation covering the rearsura complete conductor from pole to pole,

' ace of said diaphragm and periphery of said last named ole.

5 4. In a te ephonic transmitter, a casing, a dia hragm secured thereto,insulation on sai diaphragm extending to the outer pe riphery thereofand having a struck up portion forming a seat, a contact in said seat, a

10 disk of insulating material oppositely disosed to said diaphragm, acontact on said disk and ranular carbon in the space between saifdiaphragm and disk.

5. In a telephonic transmitter, a dia- 15 phragm, a casing, oppositelydisposed poles means for insulating one of said poles and said loosematerial from said casing, said other pole bein secured to the center ofsaid diaphragm, an an insulation covering the rear surface of saiddiaphragm and the periphery of said latter pole, said insulation havinga struck u portlon forming a seat for the reception of t e pole therein.

FREDERICK G. WARRELL.

Witnesses:

JOHN A. WIEDERSHEIM, C. D."M0VAY.'

